excavation是指开挖吗? excavation that do not require welding shall have side walls smoothly blended into the surrounding metal such that a slope of 10 degrees from the horizontal axis (pipe or plate) is not exceeded. the bottom of the excavation shall be prepared to a smooth basis. 不需要焊接的坡口一边管壁 可以平滑地与周围金属熔为一体,这样到管子或钢板水平轴的斜度不会超过10度。坡口底部要准备出光滑的基底。(管子焊接时,一般要打坡口,就是把管口打磨成光滑的斜坡,焊接时才能使焊料与金属很好地接合,保证焊缝的质量。但此句还是翻不通顺,请高手补充。)查看更多